But while he’s failed so far to unite the party, at least two groups seem to feel inspired by Romney: the rich and the elderly.

Michelle Cottle, writing on the Beast this morning, points to seniors as Romney’s real base, as the over-65 set is now the only age group where he’s polling now of President Obama:

Once again tonight, voters 65 and older were among Romney’s staunchest supporters. They were his best cohort in Vermont and Virginia. They may have saved his bacon in Ohio, where he walloped Santorum in this age bracket by 15 points. Even in Santorum-happy Tennessee, the seniors went Romney.

But wait! There’s more: Seniors were key to Romney’s Michigan victory. They were his biggest backers in Nevada and, more importantly, his electoral powerhouse of Florida. They were the only age bracket he won in Iowa.

As for life beyond the primary, senior voters are the only age group in which Romney is outpolling President Obama.

And Aaron Blake, writing in the Washington Post, notes that not only has Romney dominated among Republicans making $100,000 or more, according to exit polls, but that group is turning out in much higher numbers than four years ago – a boost that seems to account for the frontrunner’s very slim margins of victory in Michigan and Ohio.

To determine favorability ratings, the Election Oracle tracks 40,000 news sites, blogs, message boards, Twitter feeds, and other social-media sources to analyze what millions of people are saying about the candidates—and determines whether the Web buzz is positive or negative. That rating is weighted, along with the Real Clear Politics polling average and the latest InTrade market data, to calculate each candidate’s chances of winning the Republican nomination. See methodology here.)